386 AMERICAN HYMENOPTERA. 



naked ; mesopleura with their upper portions yellow, but at least their 

 lower halves dark ; metapleura dark, but usually with a little yellow 

 pile at their upper ends ; sides of median segment dark, but often with 

 a sprinkling of light hairs. 



Abdomen. — Dorsum: segment one clothed with yellow pile, rather 

 sparsely so in the middle ; segment two sometimes with the basal 

 middle broadly covered with yellow pile and the remainder dark, 

 sometimes with the basal half yellow and the apical half dark and 

 sometimes with the yellow extending back in the middle to the apical 

 margin with the black extending forward on the sides; segment three 

 entirely dark ; segment four usually with the basal portion dark and 

 the apical portion bearing white pile, but sometimes entirely dark ; 

 segments five and six covered with white pile. Venter mostly dark, 

 but with the apical margins of some of the segments often fringed 

 somewhat with light hairs. Hypopygium without a median carina. 



Wings. — Only slightly stained with brown ; the fore pair darkest 

 in the apical portion of the radial cell and in the region beyond the 

 veins. 



Legs. — Usually entirely dark, but the corbicular fringes sometimes 

 strongly ferruginous and the pile on the coxae and trochanters often 

 with light tinges. 



Worker. — Much like the queen ; the wings subhyaline ; the fifth dor- 

 sal abdominal segment sometimes entirely dark ; the second dorsal 

 segment often nearly or entirely covered with yellow pile. Thorax 

 with mesopleura often covered with yellow pile to the bases of the 

 legs and the metapleura often largely clothed with yellow pile. The 

 apical segments of the venter often with some whitish pile. Coxae, 

 trochanters and the bases of the femora occasionally with a noticeable 

 amount of light pile. 



Dimensions .—'Length. : queen, 13 mm. to 15| mm. ; worker, 9 mm. 

 to 13 mm. Spread of wings: queen, 28 mm. to 32| mm. ; worker, 

 19| mm. to 28 mm. Width of abdomen at second segment: queen, 

 6i mm. to 8J mm. ; worker, 4| mm. to 6^ mm. 



Habitat. — I have North American records of this species 

 from Alaska only, as follows : Kukak Bay, Kadiak and Pop- 

 off Island (all collected by Prof. Kincaid on the Harriman 

 Alaskan Expedition). I also have the following Asiatic re- 

 cords : Bering Island (Dr. L. Stejneger), Copper Island 

 (Barrett-Hamilton). It seems to be a fairly common species 

 in Alaska. 



I have seen many specimens of B. hortorum (L.) from 

 Sweden and Germany, determined both by Gerstaecker and 

 Schmiedeknecht. Some of these specimens had the basal 



